Intracranial pressure, that is, pressure within the cranial vault, is an important physical parameter to monitor in patients with intracranial hypertension because intracranial hypertension can often be controlled mechanically and pharmacologically. Physical signs and symptoms of intracranial hypertension are often difficult to interpret and can be misleading. Continuous measurement of intracranial pressure, that is, pressure within the cranial vault, provides the most reliable data base to guide the management of intracranial hypertension in a wide spectrum of neurosurgical patients.
"Intracranial pressure" has traditionally meant "intraventricular fluid pressure". The term "intracranial pressure" has become ambiguous in the last decades since different intracranial pressures have been measured in the ventricles, the subarachnoid space, the epidural space, and in the brain substance itself. The measurement of intracranial pressure in the epidural space is particularly appealing because of the non-invasive nature of the measurement. However, the epidural pressure (EDP) measurements must be highly correlated with the actual intraventricular fluid pressure before an epidural pressure measurement can be substituted for the more clinically useful intraventricular fluid pressure.
A number of sensor devices reported have presented one or more features of sensitivity, range, stability, and convenience, but none thus far has presented so many of the desired features within a single sensor system. This disclosed induction-powered-oscillator transducer system provides a high correlation between EDP measurements and IVP measurements. It further provides appropriate sensitivity and range for many applications, a slow rate of time change, and a stable mechanical structure which minimizes tissue reaction.